21002100121200 has 240 divisors, whose sum is σ = 75376384281216. Its totient is φ = 4953812198400.

The previous prime is 21002100121181. The next prime is 21002100121241. The reversal of 21002100121200 is 212100120012.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 21012522 + ... + 21989321.

Almost surely, 2^{21002100121200} is an apocalyptic number.

21002100121200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21002100121200 is an abundant number, since it is smaller than the sum of its proper divisors (54374284160016).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21002100121200 is a wasteful number, since it uses less digits than its factorization.

21002100121200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43001912 (or 43001901 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21002100121200 its reverse (212100120012), we get a palindrome (21214200241212).

The spelling of 21002100121200 in words is "twenty-one trillion, two billion, one hundred million, one hundred twenty-one thousand, two hundred".